Cutter: "Our primary mission here is to reach that structure, destroying that base is a secondary objective."

If the player loses all the units in attacking the base:

Serina: "Well, that didn't go as planned."

Eventually, UNSC forces breach the barrier blocking the entrance to the relic. Intense fighting occurs as the UNSC slowly makes their way toward the entrance. When they reach the entrance, they see the Covenant have set up a large detonator.

Cutter: "If the Covenant detonate those explosives our mission here is over! Get to the detonator!"

This is the first level players can build a base, and is therefore also the first level to train units and research upgrades.

It is possible to get over the population limit in this level by filling up the actual population limit, and then head to the landing pad for additional units. This is a handy trick for attacking the Covenant base from the front and the back.